Penicillin is a powerful antibiotic that fights bacterial infections. Who should we thank for this bacteria-blasting discovery?

In 1928, Scottish bacteriologist Alexander Fleming made the accidental discovery of a lifetime. He arrived back from vacation to a green mold, which we now know to be Penicillium notatum, killing some bacteria he'd been growing. Talk about a happy mistake!

Asked by Rachel Bortles · Last updated 5 years ago · 127.2K views · SOURCE